ABSTRACT
Think of the set of all rotations about the origin in the Euclidean plane. Let α(t) denote the rotation through the angle t counterclockwise. It can be represented by the matrix ( cos t − sin t sin t cos t ) . https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315273167/d8d3126f-3b78-4a67-b8e1-1df8c97b50c9/content/eq215.tif"/>
